The learning process during the pandemic is carried out by e-learning. Thus, an appropriate learning model is needed to improve students' critical thinking skills. This study examines the effect of problem-based learning through elearning on students' critical thinking skills during the COVID-19 pandemic. This research was conducted at SMA Islam As-Shofa Pekanbaru. This study employed quasi-experimental research with the research subjects of 10th-grade students of SMA Islam As-Shofa Pekanbaru. In practice, students were given a pretest and posttest. The research parameters are students' critical thinking skills. Indicators of critical thinking skills are analyzing, synthesizing, recognizing, solving problems, concluding, and evaluating. Data collection on critical thinking skills is pretest and posttest questions. Data were presented and analyzed inferentially. The results of students' critical thinking skills obtained an N-gain index of 0.44 (effective category). Overall, the Problem Based Learning (PBL) learning model through e-learning effectively improves students' critical thinking skills, but in detail from the five indicators, it is less effective for improving evaluation.